projects / linux-2.6-block.git / blame
| Commit | Line | Data |
|---|---|---|
| 8def3103 SH |
1 | /* |
| 2 | * System Control and Power Interface (SCPI) based CPUFreq Interface driver | |
| 3 | * | |
| 4 | * It provides necessary ops to arm_big_little cpufreq driver. | |
| 5 | * | |
| 6 | * Copyright (C) 2015 ARM Ltd. | |
| 7 | * Sudeep Holla <sudeep.holla@arm.com> | |
| 8 | * | |
| 9 | * This program is free software; you can redistribute it and/or modify | |
| 10 | * it under the terms of the GNU General Public License version 2 as | |
| 11 | * published by the Free Software Foundation. | |
| 12 | * | |
| 13 | * This program is distributed "as is" WITHOUT ANY WARRANTY of any | |
| 14 | * kind, whether express or implied; without even the implied warranty | |
| 15 | * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
| 16 | * GNU General Public License for more details. | |
| 17 | */ | |
| 18 | ||
| 19 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt | |
| 20 | ||
| 21 | #include <linux/cpufreq.h> | |
| 22 | #include <linux/module.h> | |
| 23 | #include <linux/platform_device.h> | |
| 24 | #include <linux/pm_opp.h> | |
| 25 | #include <linux/scpi_protocol.h> | |
| 26 | #include <linux/types.h> | |
| 27 | ||
| 28 | #include "arm_big_little.h" | |
| 29 | ||
| 30 | static struct scpi_ops *scpi_ops; | |
| 31 | ||
| 32 | static struct scpi_dvfs_info *scpi_get_dvfs_info(struct device *cpu_dev) | |
| 33 | { | |
| a7def561 | 34 | int domain = topology_physical_package_id(cpu_dev->id); |
| 8def3103 SH |
35 | |
| 36 | if (domain < 0) | |
| 37 | return ERR_PTR(-EINVAL); | |
| 38 | return scpi_ops->dvfs_get_info(domain); | |
| 39 | } | |
| 40 | ||
| 41 | static int scpi_opp_table_ops(struct device *cpu_dev, bool remove) | |
| 42 | { | |
| 43 | int idx, ret = 0; | |
| 44 | struct scpi_opp *opp; | |
| 45 | struct scpi_dvfs_info *info = scpi_get_dvfs_info(cpu_dev); | |
| 46 | ||
| 47 | if (IS_ERR(info)) | |
| 48 | return PTR_ERR(info); | |
| 49 | ||
| 50 | if (!info->opps) | |
| 51 | return -EIO; | |
| 52 | ||
| 53 | for (opp = info->opps, idx = 0; idx < info->count; idx++, opp++) { | |
| 54 | if (remove) | |
| 55 | dev_pm_opp_remove(cpu_dev, opp->freq); | |
| 56 | else | |
| 57 | ret = dev_pm_opp_add(cpu_dev, opp->freq, | |
| 58 | opp->m_volt * 1000); | |
| 59 | if (ret) { | |
| 60 | dev_warn(cpu_dev, "failed to add opp %uHz %umV\n", | |
| 61 | opp->freq, opp->m_volt); | |
| 62 | while (idx-- > 0) | |
| 63 | dev_pm_opp_remove(cpu_dev, (--opp)->freq); | |
| 64 | return ret; | |
| 65 | } | |
| 66 | } | |
| 67 | return ret; | |
| 68 | } | |
| 69 | ||
| 70 | static int scpi_get_transition_latency(struct device *cpu_dev) | |
| 71 | { | |
| 72 | struct scpi_dvfs_info *info = scpi_get_dvfs_info(cpu_dev); | |
| 73 | ||
| 74 | if (IS_ERR(info)) | |
| 75 | return PTR_ERR(info); | |
| 76 | return info->latency; | |
| 77 | } | |
| 78 | ||
| 79 | static int scpi_init_opp_table(struct device *cpu_dev) | |
| 80 | { | |
| 81 | return scpi_opp_table_ops(cpu_dev, false); | |
| 82 | } | |
| 83 | ||
| 84 | static void scpi_free_opp_table(struct device *cpu_dev) | |
| 85 | { | |
| 86 | scpi_opp_table_ops(cpu_dev, true); | |
| 87 | } | |
| 88 | ||
| 89 | static struct cpufreq_arm_bL_ops scpi_cpufreq_ops = { | |
| 90 | .name = "scpi", | |
| 91 | .get_transition_latency = scpi_get_transition_latency, | |
| 92 | .init_opp_table = scpi_init_opp_table, | |
| 93 | .free_opp_table = scpi_free_opp_table, | |
| 94 | }; | |
| 95 | ||
| 96 | static int scpi_cpufreq_probe(struct platform_device *pdev) | |
| 97 | { | |
| 98 | scpi_ops = get_scpi_ops(); | |
| 99 | if (!scpi_ops) | |
| 100 | return -EIO; | |
| 101 | ||
| 102 | return bL_cpufreq_register(&scpi_cpufreq_ops); | |
| 103 | } | |
| 104 | ||
| 105 | static int scpi_cpufreq_remove(struct platform_device *pdev) | |
| 106 | { | |
| 107 | bL_cpufreq_unregister(&scpi_cpufreq_ops); | |
| 108 | scpi_ops = NULL; | |
| 109 | return 0; | |
| 110 | } | |
| 111 | ||
| 112 | static struct platform_driver scpi_cpufreq_platdrv = { | |
| 113 | .driver = { | |
| 114 | .name = "scpi-cpufreq", | |
| 115 | .owner = THIS_MODULE, | |
| 116 | }, | |
| 117 | .probe = scpi_cpufreq_probe, | |
| 118 | .remove = scpi_cpufreq_remove, | |
| 119 | }; | |
| 120 | module_platform_driver(scpi_cpufreq_platdrv); | |
| 121 | ||
| 122 | MODULE_AUTHOR("Sudeep Holla <sudeep.holla@arm.com>"); | |
| 123 | MODULE_DESCRIPTION("ARM SCPI CPUFreq interface driver"); | |
| 124 | MODULE_LICENSE("GPL v2"); |